Multi-Messenger Programs in ANTARES: Status and Prospects. Véronique Van Elewyck Laboratoire AstroParticule et Cosmologie (Paris)

Transcription

1 Multi-Messenger Programs in ANTARES: Status and Prospects Laboratoire AstroParticule et Cosmologie (Paris)

2 An overview Externally triggered neutrino searches: the example of GRBs Strategies for data acquisition handling of GCN alerts ongoing searches for GRB events other photon-related searches Neutrino-triggered follow-up activities Rolling search strategy TAToO see next talk (J. Brunner) Neutrinos in coincidence with UHE cosmic rays Correlations with AUGER events Neutrinos in coincidence with gravitational waves The GWHEN project Perspectives

3 Strategies for data acquisition in ANTARES Standard data taking all raw data to shore buffered timeslices (~104 ms) Filtering algorithms: 10 Gb/s either directional (e.g. Galactic Center trigger) or scan the whole sky µ Filtering algorithms high efficiency & purity PC farm ANTARES Collaboration, NIM A570 (2007) 107 Offline analysis search for hit clusters compatible with a muon track energy threshold ~ 200 GeV 1 Mb/s Physics data average trigger rate ~ 5-15 Hz (in normal conditions of background)

4 Data taking strategies in ANTARES Data taking triggered by an external alert all raw data to shore buffered timeslices (~104 ms) alert 10 Gb/s µ Filtering algorithms PC farm 1 Mb/s Offline analysis Physics data (depending on available memory, background rate) All raw data for a limited time

5 External triggers: GRB alerts from GCN Network Data taking triggered by an external alert: the GRB alerts all raw data to shore buffered timeslices (~104 ms) alert GRB Coordinate Network (latency: ~ 5-60s) 10 Gb/s µ Filtering algorithms HETE SWIFT INTEGRAL FERMI PC farm M. Bouwhuis et al.[antares], Procs. ICRC 2009 (arxiv: ) Offline analysis 1 Mb/s Physics data All raw data for ~ 1 minute (~ 60 Gb)

6 External triggers: GRB alerts from GCN Network Status of GCN-triggered data taking typical efficiency ~90% ~ 15 Tbytes of data collected ANTARES completion mainly Swift cable failure mainly Fermi

7 External triggers: GRB alerts from GCN Network Status of GCN-triggered data taking flaring of SGR : > 100 alerts since January 22, difficult to handle! Soft Gamma-ray Repeater: X-ray pulsar with strong magnetic fields (magnetar model) soft gamma-ray flaring activity mainly Swift mainly Fermi galactic source (D~10 kpc)

8 External triggers: GRB alerts from GCN Network ANTARES Buffering often allows to recover data prior to the alert Prompt emission...to compare with: MAGIC Afterglow buffering allows to recover raw data prior to the alert time response time (s)

9 Ongoing GRB analyses Using GRB datasets blinding policy: blinding policy: - the nature of the alert is hidden (GRB, other source, fake...) - only relative times are used filtering & track reconstruction: ratio of effective volumes dedicated, looser selection - 6 hits correlated in space and time with the GRB position - GRB position used to constrain the track fit expected increase in GRB detection efficiency (from simulations) neutrino energy (GeV) Using Standard (filtered) datasets - use absolute time of the alert to define one (or more) «on-time» window - tune selection parameters on data from the «off-time» region «à la Ice Cube» filtering & track reconstruction: - basic selection (standard trigger) + quality cuts on background rate - optimization of the sensitivity based on reconstruction parameters (quality of the track fit, energy,...) & size of the search cone -- no analysis unblinded yet --

10 Other photon-correlated analyses «GRBs from above» Idea: to detect µ's created by TeV gamma-rays originating from GRBs Main channels: A and concentrate on down-going events - time-correlated analysis: study the angular correlation with GRB direction within a given time window - time-independent analysis: global excess of the µ flux in a given direction (more appropriate for steady sources) G. Guillard et al., Procs ICRC 2009 (arxiv: ) Search for neutrinos from known point sources corresponding µ flux at Earth - standard point sources search: stringent cuts to ensure low background and high resolution no significant excess found in ANTARES 5L configuration (168 active days; 94 candidate neutrinos) flux limit for a predefined list of sources - stacking analysis: uses a sample of 23 HESS galactic sources (including extended sources divided in sub-regions) (analysis ongoing) ANTARES Collaboration arxiv:

11 Neutrino triggers and follow-up all data to shore shore station ANTARES Fast online reconstruction Trigger alert optical, gamma-rays, X-rays...others M. Kowalski & A. Mohr, Astropart. Phys.27 (2007), 533

12 Neutrino triggers and follow-up all data to shore shore station Fast online reconstruction 5 to 10 ms/event alert Trigger Rolling search: - multiplet of neutrinos within given window ( ) - one high-energy neutrino ANTARES optical, gamma-rays, X-rays...others cut on reconstruction parameters: angular resolution to match the FOV of the telescope

13 Neutrino triggers and follow-up: TAToO all data to shore Fast online reconstruction Rolling Trigger alert TAToO: TAROT-ANTARES Target of Opportunity see next talk for first results! ANTARES Total latency: alert sending < 1s repositioning < 10s Appropriate to follow the time profile of different transient sources: GRB afterglows (~minutes), core-collapse SNe (~days),... TAROT (Télescope à Action Rapide pour les Objets Transitoires) FOV: 1.86º x 1.86º specialized in prompt-phase observations in optical wavelengths D. Dornic et al.[antares/tarot], Procs. ICRC 2009 (arxiv: )

14 Neutrinos in coincidence with UHECR: ongoing analyses Correlations with AUGER events Idea: compute an «inter-correlation» function between AUGER events and ANTARES events J. Petrovic, arxiv: X = neutrino look for deviations from the MC expectations under given hypotheses on the UHECR - compare with data composition & propagation: - compute correction for multiple trial factor Search for a neutrino signal in the region of CenA Idea: select a physically motivated ON region and compare the signal to OFF regions within the same declination band (same exposure) ON region: 30 x30 around CenA (SuperGalactic plane, several AUGER events correlating with Veron-Cetty AGNx)

15 Neutrinos in coincidence with gravitational waves Main motivations: - plausible common sources - Galactic: microquasars (HEN & GW emissions correlated with blob emission) SGRs (GW from star deformation during outburst, HEN from flares), - Extragalactic: GRBs (GW from core collapse into BH or coalescing NS, HEN emitted during burst) - potential for discovery of hidden sources (e.g. failed GRBs) The instruments: 600 m 3 km Michelson interferometers (mirrors suspended to free masses) 4 & 2 km 300 m 4 km VIRGO/LIGO/GEO now forming one single consortium

16 GW-HEN coincidences Started July 2009! VIRGO/LIGO detection horizon for standard binary sources: ~ 15 Mpc (~1 binary merger/ 100 years...) LIGO/VIRGO eligo/virgo+ Advanced LIGO/ Advanced VIRGO current upgrades: sensitivity x 2 probed volume x 8 Advanced detectors: sensitivity x 10 probed volume x 10 (~ 1 Gpc3,~ 40 binary mergers/yr)

17 GW-HEN coincidences Instantaneous sky coverage ANTARES + LIGO + VIRGO (geocentric coordinates) ~ 4 sr common sky 0 100

18 GW-HEN coincidences Philosophy of the analysis: Y. Aso et al., Class. Quant. Grav. 25 (2008), T. Pradier, NIM A602 (2009),268 V. Van Elewyck [ANTARES], Procs. ICRC 2009 (arxiv: ) Spatial coincidence? (overlap of likelihood skymaps)

19 GW-HEN coincidences Philosophy of the analysis: size of the time window: source/model dependant. from preliminary studies: Spatial coincidence? (overlap of likelihood skymaps)

20 GW-HEN coincidences Philosophy of the analysis: example of LIGO+VIRGO PSF (triple coincidence) angular resolution of neutrino telescope helps! Ice Cube 1 PSF Spatial coincidence? (overlap of likelihood skymaps)

21 Conclusions and perspectives Multi-messenger searches extend the capabilities of ANTARES and the reach of neutrino astronomy a coincident detection greatly enhances the significance of an observation great deal of physical information from a multi-messenger event! if no detection: the backgound can be digged deeper and stronger limits can be worked out Time-correlation of signals is an important issue ANTARES is able to handle alerts both ways with very small latency External triggers: GRB Coordinate Network (Fermi, Swift,...) potential increase in detection efficiency improve handling of flaring sources? Neutrino follow-up: TAToO (optical) future extension to other instruments is desirable: - follow-up with optical (ROTSE,...), X-rays? Gamma-rays? programs to be coordinated with Ice Cube - external triggers from GW interferometers? from Ice Cube? latency issues to be investigated